In Swiss lever escapement systems, it is known to use a double roller-impulse pin assembly as illustrated in FIG. 1. This assembly includes a roller table B which carries an impulse pin A and a safety roller C with a notch E which works with the guard-pin of pallets. Impulse pin A is fixed underneath the roller table B and works with the fork of the same pallets.
In addition to the significant height of the double roller-impulse pin assembly, it is also difficult to position impulse pin A correctly relative to notch E of safety roller C.